Syphilis is caused by

Options

A. Treponema pallidum
B. Plasmodium
C. Neisseria gonorrhea
D. Entamoeba histolytica

Answer

**Step-by-Step Solution:**

1. **Identify the Disease**: The question asks about the causative agent of syphilis, which is a sexually transmitted disease (STD).

2. **Understand the Options**: The options provided are:
- A. Treponema pallidum
- B. Plasmodium
- C. Neisseria gonorrhoeae
- D. Entamoeba histolytica

3. **Analyze Each Option**:
- **Option A: Treponema pallidum**: This is a bacterium known to cause syphilis.
- **Option B: Plasmodium**: This is a genus of parasites that causes malaria, not syphilis.
- **Option C: Neisseria gonorrhoeae**: This bacterium is responsible for gonorrhea, another STD, but not syphilis.
- **Option D: Entamoeba histolytica**: This is a protozoan that causes amoebic dysentery, unrelated to syphilis.

4. **Select the Correct Answer**: Based on the analysis, the correct answer is **Option A: Treponema pallidum**, as it is the bacterium that causes syphilis.

5. **Conclusion**: Therefore, syphilis is caused by Treponema pallidum.

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